Manufacture of low cost bits by infiltration of metal powders

ABSTRACT

An apparatus and method for manufacturing a downhole tool. The cemented matrix material is formed from a metal powder, a shoulder powder, and a binder material, wherein the metal powder and/or the shoulder powder includes at least one of stainless steel powder, nickel powder, cobalt powder, iron powder, or powders of other suitable metals or alloys, or a combination of such mentioned powders.

CROSS-REFERENCE TO RELATED APPLICATIONS

This present application claims priority to U.S. Provisional PatentApplication No. 61/943,141, entitled “Manufacture Of Low Cost Bits ByInfiltration Of Metal Powders,” filed Feb. 21, 2014, the disclosure ofwhich is incorporated herein.

BACKGROUND OF THE INVENTION

This invention relates generally to downhole tools and methods formanufacturing such items. More particularly, this invention relates tolow cost infiltrated metal powders used in drilling products including,but not limited to, fixed cutter bits, polycrystalline diamond compact(“PDC”) drill bits, natural diamond drill bits, thermally stablepolycrystalline (“TSP”) drill bits, bi-center bits, core bits, andreamers and stabilizers, and the methods of manufacturing such items.

Full hole tungsten carbide matrix drill bits for oilfield applicationshave been manufactured and used in drilling since at least as early asthe 1940's. FIG. 1 shows a cross-sectional view of a downhole toolcasting assembly 100 in accordance with the prior art. The downhole toolcasting assembly 100 consists of a thick-walled mold 110, a stalk 120,one or more nozzle displacements 122, a blank 124, a funnel 140, and abinder pot 150. The downhole tool casting assembly 100 is used tofabricate a casting 200 (FIG. 2) of a downhole tool 200 (FIG. 2), suchas a drill bit 200 (FIG. 2).

According to a typical downhole tool casting assembly 100, as shown inFIG. 1, and a method for using the downhole tool casting assembly 100,the thick-walled mold 110 is fabricated with a precisely machinedinterior surface 112, and forms a mold volume 114 located within theinterior of the thick-walled mold 110. The thick-walled mold 110 is madefrom sand, hard carbon graphite, ceramic, or other known suitablematerials. The precisely machined interior surface 112 has a shape thatis a negative of what will become the facial features of the eventualbit face. The precisely machined interior surface 112 is milled anddressed to form the proper contours of the finished bit 200 (FIG. 2).Various types of cutters 240 (FIG. 2), known to persons having ordinaryskill in the art, can be placed along the locations of the cutting edgesof the bit 200 (FIG. 2) and can also be optionally placed along thegauge area 250 (FIG. 2) of the bit 200 (FIG. 2). These cutters 240 (FIG.2) can be placed during the bit fabrication process or after the bit 200(FIG. 2) has been fabricated via brazing or other methods known topersons having ordinary skill in the art.

Once the thick-walled mold 110 is fabricated, displacements are placedat least partially within the mold volume 114 of the thick-walled mold110. The displacements are typically fabricated from clay, sand,graphite, ceramic, or other known suitable materials. Thesedisplacements consist of the center stalk 120 and the at least onenozzle displacement 122. The center stalk 120 is positionedsubstantially within the center of the thick-walled mold 110 andsuspended a desired distance from the bottom of the mold's interiorsurface 112. The nozzle displacements 122 are positioned within thethick-walled mold 110 and extend from the center stalk 120 to the bottomof the mold's interior surface 112. The center stalk 120 and the nozzledisplacements 122 are later removed from the eventual drill bit casting200 (FIG. 2) so that drilling fluid (not shown) can flow though thecenter of the finished bit 200 (FIG. 2) during the drill bit'soperation.

The blank 124 is a cylindrical steel casting mandrel that is centrallysuspended at least partially within the thick-walled mold 110 and aroundthe center stalk 120. The blank 124 is positioned a predetermineddistance down in the thick-walled mold 110. According to the prior art,the distance between the outer surface of the blank 124 and the interiorsurface 112 of the thick-walled mold 110 is typically twelve millimeters(“mm”) or more so that potential cracking of the thick-walled mold 110is reduced during the casting process.

Once the displacements 120, 122 and the blank 124 have been positionedwithin the thick-walled mold 110, tungsten carbide powder 130, whichincludes some free tungsten, is loaded into the thick-walled mold 110 sothat it fills a portion of the mold volume 114 that is around the lowerportion of the blank 124, between the inner surfaces of the blank 124and the outer surfaces of the center stalk 120, and between the nozzledisplacements 122. Shoulder powder 134 is loaded on top of the tungstencarbide powder 130 in an area located at both the area outside of theblank 124 and the area between the blank 124 and the center stalk 120.The shoulder powder 134 is made of tungsten powder. This shoulder powder134 acts to blend the casting to the steel blank 124 and is machinable.Once the tungsten carbide powder 130 and the shoulder powder 134 areloaded into the thick-walled mold 110, the thick-walled mold 110 istypically vibrated to improve the compaction of the tungsten carbidepowder 130 and the shoulder powder 134. Although the thick-walled mold110 is vibrated after the tungsten carbide powder 130 and the shoulderpowder 134 are loaded into the thick-walled mold 110, the vibration ofthe thick-walled mold 110 can be done as an intermediate step before,during, and/or after the shoulder powder 134 is loaded on top of thetungsten carbide powder 130.

The funnel 140 is a graphite cylinder that forms a funnel volume 144therein. The funnel 140 is coupled to the top portion of thethick-walled mold 110. A recess 142 is formed at the interior edge ofthe funnel 140, which facilitates the funnel 140 coupling to the upperportion of the thick-walled mold 110. Typically, the inside diameter ofthe thick-walled mold 110 is similar to the inside diameter of thefunnel 140 once the funnel 140 and the thick-walled mold 110 are coupledtogether.

The binder pot 150 is a cylinder having a base 156 with an opening 158located at the base 156, which extends through the base 156. The binderpot 150 also forms a binder pot volume 154 therein for holding a bindermaterial 160. The binder pot 150 is coupled to the top portion of thefunnel 140 via a recess 152 that is formed at the exterior edge of thebinder pot 150. This recess 152 facilitates the binder pot 150 couplingto the upper portion of the funnel 140. Once the downhole tool castingassembly 100 has been assembled, a predetermined amount of bindermaterial 160 is loaded into the binder pot volume 154. The typicalbinder material 160 is a copper alloy or other suitable known materialand may include some flux powder. Although one example has been providedfor setting up the downhole tool casting assembly 100, other examplescan be used to form the downhole tool casting assembly 100. For example,the mold 110 and the funnel 140 are formed as a single component.

The downhole tool casting assembly 100 is placed within a furnace (notshown) or other heating structure. The binder material 160 melts andflows into the tungsten carbide powder 130 through the opening 158 ofthe binder pot 150. In the furnace, the molten binder material 160infiltrates the tungsten carbide powder 130 and the shoulder powder 134to fill the interparticle spaces formed between adjacent particles oftungsten carbide powder 130 and between adjacent particles of shoulderpowder 134. During this process, a substantial amount of binder material160 is used so that it fills at least a substantial portion of thefunnel volume 144. This excess binder material 160 in the funnel volume144 supplies a downward force on the tungsten carbide powder 130 and theshoulder powder 134. Once the binder material 160 completely infiltratesthe tungsten carbide powder 130 and the shoulder powder 134, thedownhole tool casting assembly 100 is pulled from the furnace and iscontrollably cooled. Upon cooling, the binder material 160 solidifiesand cements the particles of tungsten carbide powder 130 and theshoulder powder 134 together into a coherent integral mass (not shown).The binder material 160 also bonds this coherent integral mass to thesteel blank 124. The coherent integral mass and the blank 124collectively form the matrix body bit 200 (FIG. 2). Once cooled, thethick-walled mold 110 is broken away from the casting 200 (FIG. 2). Thecasting 200 (FIG. 2) then undergoes finishing steps which are known topersons having ordinary skill in the art, including the addition of athreaded connection 220 (FIG. 2) coupled to the top portion of the blank124. Although the matrix body bit 200 (FIG. 2), or casting 200 (FIG. 2),has been described to be formed using the process and equipmentdescribed above, the process and/or the equipment can be varied to formthe matrix body bit 200 (FIG. 2).

FIG. 2 shows a perspective view of a conventional drill bit 200, orconventional fixed cutter drill bit 200, in accordance with the priorart. Referring to FIG. 2, the conventional drill bit 200 includes a bitbody 210 that is coupled to the shank 124 and is designed to rotate in acounter-clockwise direction 290. The shank 124 is coupled to an APIconnection 216 which includes a threaded connection 217 at one end 220.The threaded connection 217 couples to a drill string (not shown) orsome other equipment that is coupled to the drill string. The threadedconnection 217 is shown to be positioned on the exterior surface of theone end 220. This positioning assumes that the conventional drill bit200 is coupled to a corresponding threaded connection located on theinterior surface of a drill string (not shown). However, the threadedconnection 217 at the one end 220 is alternatively positioned on theinterior surface of the one end 220 if the corresponding threadedconnection of the drill string, or other equipment, is positioned on itsexterior surface in other exemplary embodiments. A bore (not shown) isformed longitudinally through the shank 124 and extends into the bitbody 210 forming a plenum (not shown), which communicates drilling fluidduring drilling operations from within the bit body 210 to a drill bitface 211 via one or more conventional nozzle sockets 214 formed withinthe bit body 210. These conventional nozzle sockets 214 arecylindrically shaped within the conventional drill bit 200.

The bit body 210 includes a plurality of gauge sections 250 and aplurality of blades 230 extending from the drill bit face 211 of the bitbody 210 towards the threaded connection 217, where each blade 230extends to and terminates at a respective gauge section 250. The blade230 and the respective gauge section 250 are formed as a singlecomponent, but are formed separately in certain other conventional drillbits 200. The drill bit face 211 is positioned at one end of the bitbody 210 furthest away from the shank 124. The plurality of blades 230form the cutting surface of the conventional drill bit 200. One or moreof these plurality of blades 230 are either coupled to the bit body 210or are integrally formed with the bit body 210. The gauge sections 250are positioned at an end of the bit body 210 adjacent the shank 124. Thegauge section 250 includes one or more gauge cutters (not shown) incertain conventional drill bits 200. The gauge sections 250 typicallydefine and hold the full hole diameter of the drilled hole. The blades230 and/or the gauge sections 250 are oriented in a spiral configurationaccording to some of the prior art. However, in other conventional drillbits, the blades 230 and/or the gauge sections 250 are oriented in anon-spiral configuration. A junk slot 222 is formed, or milled, betweeneach consecutive blade 230, which allows for cuttings and drilling fluidto return to the surface of the wellbore (not shown) once the drillingfluid is discharged from the nozzle sockets 214 during drillingoperations.

A plurality of cutters 240 are coupled to each of the blades 230 withina respective cutter pocket 260 formed therein. The cutters 240 aregenerally formed in an elongated cylindrical shape; however, thesecutters 240 can be formed in other shapes, such as disc-shaped orconical-shaped. The cutters 240 typically include a substrate 242,oftentimes cylindrically shaped, and a cutting surface 244, alsocylindrically shaped, disposed at one end of the substrate 242 andoriented to extend outwardly from the blade 230 when coupled within therespective cutter pocket 260. The cutting surface 244 can be formed froma hard material, such as bound particles of polycrystalline diamondforming a diamond table, and be disposed on or coupled to asubstantially circular profiled end surface of the substrate 242 of eachcutter 240. Typically, the polycrystalline diamond cutters (“PDC”) arefabricated separately from the bit body 210 and are secured within arespective cutter pocket 260 formed within the bit body 210. Althoughone type of cutter 240 used within the conventional drill bit 200 is aPDC cutter; other types of cutters also are contemplated as being usedwithin the conventional drill bit 200. These cutters 240 and portions ofthe bit body 210 deform the earth formation by scraping and/or shearingdepending upon the type of conventional drill bit 200.

The tungsten carbide matrix used in forming the drill bit 200 is verybrittle, not hard, and not ductile; thereby causing eventual failure ofthe bit 200 during drilling operations. Further, the cost of tungstencarbide 130 (FIG. 1) and tungsten 134 (FIG. 1) powders used in formingthe drill bit 200 are relatively expensive. There is a need to fabricatedownhole tools using cheaper materials, either alone or in combinationwith the tungsten carbide 130 (FIG. 1) and/or tungsten 134 (FIG. 1)powders thereby using less tungsten carbide 130 (FIG. 1) and/or tungsten134 (FIG. 1) powders and making the bit 200 lower costing. Further,there is a need to use other materials in fabricating these downholetools to modify the properties of the coherent integral mass, or bitbody 210, allowing the downhole tool 200 perform better and last longerin the hole.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features and aspects of the invention will bebest understood with reference to the following description of certainexemplary embodiments of the invention, when read in conjunction withthe accompanying drawings, wherein:

FIG. 1 shows a cross-sectional view of a downhole tool casting assemblyin accordance with the prior art;

FIG. 2 shows a perspective view of a conventional fixed cutter drill bitin accordance with the prior art;

FIG. 3 shows a cross-sectional view of a downhole tool casting assemblyin accordance with an exemplary embodiment of the invention; and

FIG. 4 shows a partial cross-sectional view of a downhole tool castingformed using the downhole tool casting assembly of FIG. 3 in accordancewith the exemplary embodiment.

DETAILED DESCRIPTION OF THE INVENTION

This invention relates generally to downhole tools and methods formanufacturing such items. More particularly, this invention relates tolow cost infiltrated metal powders used in drilling products including,but not limited to, fixed cutter bits, polycrystalline diamond compact(“PDC”) drill bits, natural diamond drill bits, thermally stablepolycrystalline (“TSP”) drill bits, bi-center bits, core bits, andreamers and stabilizers, and the methods of manufacturing such items.Although the description provided below is related to a drill bit,embodiments of the present invention relate to any infiltrated metalpowders used to fabricate a drilling product.

FIG. 3 shows a cross-sectional view of a downhole tool casting assembly300 in accordance with the exemplary embodiment. Referring to FIG. 3,the downhole tool casting assembly 300 includes a mold 310, a stalk 320,one or more nozzle displacements 322, a blank 324, a funnel 340, and abinder pot 350. The downhole tool casting assembly 300 is used tofabricate a casting 400 (FIG. 4) of a downhole tool, such as a fixedcutter bit, a PDC drill bit, a natural diamond drill bit, and a TSPdrill bit. However, the downhole tool casting assembly 300 is modifiedin other exemplary embodiments to fabricate other downhole tools, suchas a bi-center bit, a core bit, and a matrix bodied reamer andstabilizer.

The mold 310 is fabricated with a precisely machined interior surface312, and forms a mold volume 314 located within the interior of the mold310. The mold 310 is made from sand, hard carbon graphite, ceramic, orother known suitable materials. The precisely machined interior surface312 has a shape that is a negative of what will become the facialfeatures of the eventual bit face. The precisely machined interiorsurface 312 is milled and dressed to form the proper contours of thefinished bit. Various types of cutters, such as the cutters 240 (FIG.2), known to persons having ordinary skill in the art, are placed alongthe locations of the cutting edges of the bit and are optionally placedalong the gage area of the bit. These cutters are placed during the bitfabrication process or after the bit has been fabricated via brazing orother methods known to persons having ordinary skill in the art.

Once the mold 310 is fabricated, displacements are placed at leastpartially within the mold volume 314. The displacements are fabricatedfrom clay, sand, graphite, ceramic, or other known suitable materials.These displacements include the center stalk 320 and the at least onenozzle displacement 322. The center stalk 320 is positionedsubstantially within the center of the mold 310 and suspended a desireddistance from the bottom of the mold's interior surface 312. The nozzledisplacements 322 are positioned within the mold 310 and extend from thecenter stalk 320 to the bottom of the mold's interior surface 312. Thecenter stalk 320 and the nozzle displacements 322 are later removed fromthe eventual drill bit casting so that drilling fluid (not shown) flowsthough the center of the finished bit during the drill bit's operation.

The blank 324, which has been previously described above with respect toblank 124, is centrally suspended at least partially within the mold 310and around the center stalk 320. The blank 324 is positioned apredetermined distance down in the mold 310. The distance between theouter surface of the blank 324 and the interior surface 312 of the mold310 is about twelve millimeters or more so that potential cracking ofthe mold 310 is reduced during the casting process. However, thisdistance is varied in other exemplary embodiments depending upon thestrength of the mold 310 or the method and/or equipment used infabricating the casting. According to some exemplary embodiments, acoating (not shown) may optionally be applied to at least a portion ofthe surface of the blank 324. This coating may be applied to improve thebonding between the powders 330, 334, which are described in more detailbelow, and the blank 324.

Once the displacements 320, 322 and the blank 324 have been positionedwithin the mold 310, metal powder 330 is loaded into the mold 110 sothat it fills a portion of the mold volume 314 that is around at least alower portion of the blank 324, between the inner surfaces of the blank324 and the outer surfaces of the center stalk 320, and between thenozzle displacements 322. Shoulder powder 334 is loaded on top of themetal powder 330 in an area located at both the area outside of theblank 324 and the area between the blank 324 and the center stalk 320.According to some exemplary embodiments, the metal powder 330 and theshoulder powder 334 are the same powders with the same or similarcompositions. However, in other exemplary embodiments, the metal powder330 and the shoulder powder 334 are different powders, having some ornone of the powder materials being the same. Also, the metal powder 330and the shoulder powder 334 may have the same material but at adifferent composition, according to some exemplary embodiments.

According to some exemplary embodiments, the metal powder 330 includesat least one of stainless steel powder, nickel powder, cobalt powder,iron powder, or powders of other suitable metals or alloys, or acombination of such mentioned powders. According to some exemplaryembodiments, the metal powder 330 is formed of at least more than 25% ofat least one of these powders mentioned immediately above. For example,the metal powder 330 is formed of at least more than 25% of at least oneof stainless steel powder, nickel powder, cobalt powder, iron powder, ora combination of such mentioned powders. According to some otherexemplary embodiments, the metal powder 330 is formed of at least morethan 30% of at least one of these powders mentioned immediately above.In yet other exemplary embodiments, the metal powder 330 is formed of atleast more than 40% of at least one of these powders mentionedimmediately above. In an alternative exemplary embodiment, the metalpowder 330 is formed with less than 25% of tungsten carbide powders. Inyet another alternative exemplary embodiment, the metal powder 330 isformed with less than 20% of tungsten carbide powders. In yet anotherexemplary embodiment, the metal powder 330 is formed with less than 15%of tungsten carbide powders.

According to some exemplary embodiments, the shoulder powder 334includes at least one of stainless steel powder, nickel powder, cobaltpowder, iron powder, or powders of other suitable metals or alloys, or acombination of such mentioned powders. According to some exemplaryembodiments, the shoulder powder 334 is formed of at least more than 25%of at least one of these powders mentioned immediately above. Forexample, the shoulder powder 334 is formed of at least more than 25% ofat least one of stainless steel powder, nickel powder, cobalt powder,iron powder, or a combination of such mentioned powders. According tosome other exemplary embodiments, the shoulder powder 334 is formed ofat least more than 30% of at least one of these powders mentionedimmediately above. In yet other exemplary embodiments, the shoulderpowder 334 is formed of at least more than 40% of at least one of thesepowders mentioned immediately above. In an alternative exemplaryembodiment, the shoulder powder 334 is formed with less than 25% oftungsten powders. In yet another alternative exemplary embodiment, theshoulder powder 334 is formed with less than 20% of tungsten powders. Inyet another exemplary embodiment, the shoulder powder 334 is formed withless than 15% of tungsten powders.

Once the metal powder 330 and the shoulder powder 334 are loaded intothe mold 310, the mold 310 is vibrated, in some exemplary embodiments,to improve the compaction of the tungsten carbide powder 330 and theshoulder powder 334. Although the mold 310 is vibrated after the metalpowder 330 and the shoulder powder 334 are loaded into the mold 310, thevibration of the mold 310 is done as an intermediate step before,during, and/or after the shoulder powder 334 is loaded on top of themetal powder 330.

The funnel 340 is a graphite cylinder that forms a funnel volume 344therein. The funnel 340 is coupled to the top portion of the mold 310. Arecess 342 is formed at the interior edge of the funnel 340, whichfacilitates the funnel 340 coupling to the upper portion of the mold310. In some exemplary embodiments, the inside diameter of the mold 310is similar to the inside diameter of the funnel 340 once the funnel 340and the mold 310 are coupled together.

The binder pot 350 is a cylinder having a base 356 with an opening 358located at the base 356, which extends through the base 356. The binderpot 350 also forms a binder pot volume 354 therein for holding a bindermaterial 360. The binder pot 350 is coupled to the top portion of thefunnel 340 via a recess 352 that is formed at the exterior edge of thebinder pot 350. This recess 352 facilitates the binder pot 350 couplingto the upper portion of the funnel 340. Once the downhole tool castingassembly 300 has been assembled, a predetermined amount of bindermaterial 360 is loaded into the binder pot volume 354. The typicalbinder material 360 is a copper alloy or other suitable known material.According to some exemplary embodiments, the binder material 360, orbraze material, includes MF53 and a small amount of B-1 dry Handyfloflux powder, which are known to people having ordinary skill in the art.Although one example has been provided for setting up the downhole toolcasting assembly 300, other examples having greater, fewer, or differentcomponents are used to form the downhole tool casting assembly 300. Forinstance, the mold 310 and the funnel 340 are combined into a singlecomponent in some exemplary embodiments.

The downhole tool casting assembly 300 is placed within a furnace (notshown) or other heating structure to undergo a brazing process. Duringthe brazing process, the binder material 360 melts and flows into theshoulder powder 334 and the metal powder 330 through the opening 358 ofthe binder pot 350. In the furnace, the molten binder material 360infiltrates the metal powder 330 and the shoulder powder 334 to fill theinterparticle spaces formed between adjacent particles of metal powder330 and/or shoulder powder 334. During this process, a substantialamount of binder material 360 is used so that it fills at least asubstantial portion of the funnel volume 344. This excess bindermaterial 360 in the funnel volume 344 supplies a downward force on themetal powder 330 and the shoulder powder 334. According to someexemplary embodiments, the brazing process is performed in airatmosphere at a brazing temperature in excess of 2100° F. and for a timecommensurate with the downhole tool 400 (FIG. 4), or bit, size. Forexample, for a 8″ bit size, the downhole tool casting assembly 300 isplaced at a temperature in of 2100° F. for about one hour.

Once the binder material 360 completely infiltrates the metal powder 330and the shoulder powder 334, the downhole tool casting assembly 300 ispulled from the furnace and is controllably cooled. Upon cooling, thebinder material 360 solidifies and cements the particles of metal powder330 and shoulder powder 334 together into a coherent integral mass 410(FIG. 4). The binder material 360 also bonds this coherent integral mass410 (FIG. 4) to the blank 324, according to certain exemplaryembodiments. The coherent integral mass 410 (FIG. 4) and the blank 324collectively form the infiltrated bit 400 (FIG. 4), a portion of whichis shown in FIG. 4. Once cooled, the mold 310 is broken away from thecasting. The casting then undergoes finishing steps which are known topersons of ordinary skill in the art, including cleaning of the castingand the coupling of a threaded connection (not shown) or AISI 4140 uppersection, similar to API connection 216 (FIG. 2), to the top portion ofthe blank 324. According to certain exemplary embodiments, the AISI 4140upper section is welded to the blank 324 by submerged arc welding(“SAW”) or gas metal arc welding (“GMAW”) according to the usual methodof manufacture. Further, according to some exemplary embodiments, aprotective layer of plasma transferred ARC (“PTA”) is applied onto atleast a portion of the downhole tool, such as the surface of the blades,so that the downhole tool can better handle abrasion. Although theinfiltrated bit 400 (FIG. 4) has been described to be formed using theprocess and equipment described above, the process and/or the equipmentcan be varied to still form the infiltrated bit 400 (FIG. 4).

FIG. 4 shows a partial cross-sectional view of a downhole tool casting400 formed using the downhole tool casting assembly 300 of FIG. 3 inaccordance with the exemplary embodiment. Referring to FIG. 4, thedownhole tool casting 400 includes the coherent integral mass 410, theblank 324, and the passageways 420 formed from the removal of thedisplacements 320, 322 (FIG. 3). As mentioned above with respect to FIG.3, the coherent integral mass 410 is formed using the metal powder 330(FIG. 3), as described above, and the shoulder powder 334 (FIG. 3), alsoas described above. The metal powder 330 (FIG. 3) and the shoulderpowder 334 (FIG. 3) are infiltrated with binder material 360 (FIG. 3) toform infiltrated metal powder 430 and infiltrated shoulder powder 434,respectively. According to the exemplary embodiment illustrated in FIGS.3 and 4, the infiltrated shoulder powder 434 may be of the same ordifferent composition and/or of the same or different powder materialsthan the infiltrated metal powder 430.

According to exemplary embodiments, the metal powders and/or theshoulder powders used to manufacture the downhole tool provide improvedcharacteristics than those used in the prior art. As previouslymentioned, the tungsten carbide powder has been used in lieu of theabove described metal powders and tungsten powder has been used in lieuof the shoulder powder mentioned above. When testing an infiltratednickel sample using a Charpy test, the force needed to break the samplewas found to be 9 ft-lbs, while the force needed to break tungstencarbide matrix sample was 1 ft-lbs at the same conditions. Thus, theinfiltrated nickel sample was found to be about 9 times stronger.Similarly, an infiltrated stainless steel sample was found to need 50ft-lbs to break the sample at the same conditions, thereby making itabout 50 times stronger than the tungsten carbide matrix sample.Further, the infiltrated nickel sample was found to have a hardness ofHBW 84, whereas the tungsten carbide matrix sample is very brittle thathardness tests are generally not performed on it. The infiltratedstainless steel sample was found to have a hardness of HBW 103. Withrespect to ductile tests, the infiltrated nickel sample was found to bemore ductile than the tungsten carbide matrix sample, and theinfiltrated stainless steel sample was found to be more ductile than theinfiltrated nickel sample. The infiltrated nickel sample was found tohave a yield lbs. of 1,160, an ultimate load lbs. of 2,730, a yieldP.S.I. of 24,200 and a tensile P.S.I. of 57,000, while the infiltratedstainless steel sample was found to have a yield lbs. of 2,330, anultimate load lbs. of 4,470, a yield P.S.I. of 47,900, and a tensileP.S.I. of 91,700. Both nickel powder and stainless steel powder arecheaper than those powders presently used.

Although the invention has been described with reference to specificembodiments, these descriptions are not meant to be construed in alimiting sense. Various modifications of the disclosed embodiments, aswell as alternative embodiments of the invention will become apparent topersons skilled in the art upon reference to the description of theinvention. It should be appreciated by those skilled in the art that theconception and the specific embodiments disclosed may be readilyutilized as a basis for modifying or designing other structures forcarrying out the same purposes of the invention. It should also berealized by those skilled in the art that such equivalent constructionsdo not depart from the spirit and scope of the invention as set forth inthe appended claims. It is therefore, contemplated that the claims willcover any such modifications or embodiments that fall within the scopeof the invention.

What is claimed is:
 1. A downhole tool, comprising: a metal componentcomprising a top portion, a bottom portion, and a channel extending fromthe top portion to the bottom portion; and an infiltrated metal powderbonded to an exterior surface and an interior surface of the metalcomponent, the infiltrated metal powder formed from infiltration of abinder material with a metal powder, the infiltrated metal powdercoupled to at least the bottom portion of the metal component; aninfiltrated shoulder powder bonded to an exterior surface and aninterior surface of the metal component, the infiltrated shoulder powderformed from infiltration of the binder material with a shoulder powder,the infiltrated shoulder powder coupled to at least the top portion ofthe metal component, the infiltrated shoulder powder being positionedabove the infiltrated metal powder, wherein at least one of the metalpowder or shoulder powder used for fabricating the downhole toolcomprises: at least one of stainless steel powder, nickel powder, cobaltpowder, iron powder, or a combination of two or more of these powders;and a concentration of less than 25% of a tungsten carbide powder or atungsten powder, respectively.
 2. The downhole tool of claim 1, whereinthe metal powder comprises at least one of stainless steel powder,nickel powder, cobalt powder, iron powder, or a combination of two ormore of these powders and a concentration of less than 25% of thetungsten carbide powder.
 3. The downhole tool of claim 1, wherein theshoulder powder comprises at least one of stainless steel powder, nickelpowder, cobalt powder, iron powder, or a combination of two or more ofthese powders and a concentration of less than 25% of the tungstenpowder.
 4. The downhole tool of claim 1, wherein the metal powder andthe shoulder powder comprise at least one of stainless steel powder,nickel powder, cobalt powder, iron powder, or a combination of two ormore of these powders and a concentration of less than 25% of thetungsten carbide powder and the tungsten powder, respectively.
 5. Thedownhole tool of claim 1, wherein the metal powder is the samecomposition as the shoulder powder.
 6. The downhole tool of claim 1,wherein the metal powder is a different composition than the shoulderpowder.
 7. The downhole tool of claim 6, wherein the metal powder andthe shoulder powder comprise the same powders.
 8. The downhole tool ofclaim 1, wherein the metal powder is formed of at least more than 25% ofat least one of stainless steel powder, nickel powder, cobalt powder,iron powder, or a combination of two or more of these powders.
 9. Thedownhole tool of claim 1, wherein the metal powder is formed of at leastmore than 30% of at least one of stainless steel powder, nickel powder,cobalt powder, iron powder, or a combination of two or more of thesepowders.
 10. The downhole tool of claim 1, wherein the metal powder isformed of at least more than 40% of at least one of stainless steelpowder, nickel powder, cobalt powder, iron powder, or a combination oftwo or more of these powders.
 11. The downhole tool of claim 1, whereinthe shoulder powder is formed of at least more than 25% of at least oneof stainless steel powder, nickel powder, cobalt powder, iron powder, ora combination of two or more of these powders.
 12. The downhole tool ofclaim 1, wherein the shoulder powder is formed of at least more than 30%of at least one of stainless steel powder, nickel powder, cobalt powder,iron powder, or a combination of two or more of these powders.
 13. Thedownhole tool of claim 1, wherein the shoulder powder is formed of atleast more than 40% of at least one of stainless steel powder, nickelpowder, cobalt powder, iron powder, or a combination of two or more ofthese powders.
 14. The downhole tool of claim 1, wherein at least one ofthe metal powder or the shoulder powder comprise a concentration of lessthan 20% of a tungsten carbide powder or a tungsten powder,respectively.
 15. The downhole tool of claim 1, wherein at least one ofthe metal powder or the shoulder powder comprise a concentration of lessthan 15% of a tungsten carbide powder or a tungsten powder,respectively.
 16. A method for manufacturing a downhole tool,comprising: placing a blank within a downhole tool casting assembly, theblank comprising a top portion, a bottom portion, and a channelextending from the top portion to the bottom portion; placing a mixturearound at least a portion of the surface of the blank within thedownhole tool casting assembly, the mixture comprising a metal powderand a shoulder powder, the metal powder positioned adjacent at least thebottom portion of the blank and the shoulder powder being positionedadjacent to at least the top portion of the blank, the shoulder powderbeing positioned above the metal powder; melting a binder material intothe mixture; forming an infiltrated metal powder and an infiltratedshoulder powder from the mixture and the binder material; and bondingthe infiltrated metal powder and the infiltrated shoulder powder to theblank, wherein at least one of the metal powder or shoulder powder usedfor fabricating the downhole tool comprises: at least one of stainlesssteel powder, nickel powder, cobalt powder, iron powder, or acombination of two or more of these powders; and a concentration of lessthan 25% of a tungsten carbide powder or a tungsten powder,respectively.
 17. The method of claim 16, wherein the metal powdercomprises at least one of stainless steel powder, nickel powder, cobaltpowder, iron powder, or a combination of two or more of these powdersand a concentration of less than 25% of the tungsten carbide powder. 18.The method of claim 16, wherein the shoulder powder comprises at leastone of stainless steel powder, nickel powder, cobalt powder, ironpowder, or a combination of two or more of these powders and aconcentration of less than 25% of the tungsten powder.
 19. The method ofclaim 16, wherein the metal powder and the shoulder powder comprise atleast one of stainless steel powder, nickel powder, cobalt powder, ironpowder, or a combination of two or more of these powders and aconcentration of less than 25% of the tungsten carbide powder and thetungsten powder, respectively.
 20. The method of claim 16, wherein themetal powder is the same composition as the shoulder powder.
 21. Themethod of claim 16, wherein the metal powder is a different compositionthan the shoulder powder.
 22. The method of claim 21, wherein the metalpowder and the shoulder powder comprise the same powders.
 23. The methodof claim 16, wherein the metal powder is formed of at least more than25% of at least one of stainless steel powder, nickel powder, cobaltpowder, iron powder, or a combination of two or more of these powders.24. The method of claim 16, wherein the metal powder is formed of atleast more than 30% of at least one of stainless steel powder, nickelpowder, cobalt powder, iron powder, or a combination of two or more ofthese powders.
 25. The method of claim 16, wherein the metal powder isformed of at least more than 40% of at least one of stainless steelpowder, nickel powder, cobalt powder, iron powder, or a combination oftwo or more of these powders.
 26. The method of claim 16, wherein theshoulder powder is formed of at least more than 25% of at least one ofstainless steel powder, nickel powder, cobalt powder, iron powder, or acombination of two or more of these powders.
 27. The method of claim 16,wherein the shoulder powder is formed of at least more than 30% of atleast one of stainless steel powder, nickel powder, cobalt powder, ironpowder, or a combination of two or more of these powders.
 28. The methodof claim 16, wherein the shoulder powder is formed of at least more than40% of at least one of stainless steel powder, nickel powder, cobaltpowder, iron powder, or a combination of two or more of these powders.29. The method of claim 16, wherein at least one of the metal powder orthe shoulder powder comprise a concentration of less than 20% of atungsten carbide powder or a tungsten powder, respectively.
 30. Themethod of claim 16, wherein at least one of the metal powder or theshoulder powder comprise a concentration of less than 15% of a tungstencarbide powder or a tungsten powder, respectively.
 31. The method ofclaim 16, further comprising applying a hardfacing material onto atleast a portion of the downhole tool.